Abstract: Desorption behaviors of cyclohexane gas on activated carbon of iodine adsorber was investigated. Effects of temperature, relative humidity, flow rate, cyclohexane concentration of carrier gas, and thickness of carbon bed were carefully studied to provide technical support for the application of the cyclohexane method in leakage test of iodine adsorber system. Experimental results showed that cyclohexane could be retained for about 500 min in activated carbon bed under the condition of 40 ℃ and 30% relative humidity. The retention time decreased with the increase of temperature, relative humidity, concentration of cyclohexane and flow rate of carrier gas, with the most significant effect from temperature. An experimental result demonstrated that cyclohexane could be used at high humidity conditions to test leakage of iodine adsorber because the retention time of cyclohexane in activated carbon could still reach 90 min at 100 ppm(10^-6) of cyclohexane and 80% of relative humidity.

Key words: nuclear power plant, iodine adsorber, leakage rate, cyclohexane, desorption